The Columbia University Specialized Center of Research in Arteriosclerosis comprises a multidisciplinary program of clinical and laboratory research directed at major questions in the areas of lipid and lipoprotein metablism, hyperlipidemia, atherogenesis, thrombosis and coronary heart disease. Two major integrating themes are: 1) studies of interrelationships between lipoproteins, platelets and the arterial wall; and 2) studies on the metabolism of plasma lipoproteins and apolipoproteins. The SCOR is composed of 7 units. Unit #1 consists of several core facilities (Core Clinic, Lipid Laboratory, Biomathematics/Biostatistics Resource, Tissue Culture Laboratory) that support all Units of the SCOR. Unit #2, includes studies on cholesterol metabolism in intact humans, and studies on the biochemistry and metabolism of plasma retinol-binding protein. Unit #3 involves studies on the normal and abnormal regulation of coronary blood flow in experimental animals and in humans. These studies explore, amongst other things, aspects of the roles and regulation of prostaglandins, platelets, the sympathetic nervous system, and catecholamines. Unit #4 aims to explore relationships between the hemostatic system and atherosclerosis. Unit #5 involves studies on the interactions of plasma lipoproteins with cells in tissue culture, on the metabolism of apolipoprotein E, and on the postheparin lipases (hepatic triglyceride lipase and lipoprotein lipase). Unit #6 has the overall goal of delineating the role of the intestine in the production and metabolism of HDL and in the regulation of plasma HDL levels. Unit #7 comprises a cell biology program that aims to explore the mechanisms and processes that regulate cell proliferation in the vessel wall, including studies of the mitogens PDGF and endothelial cell-derived growth factor (EDGF).